/*
    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU Lesser General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/
import java.util.Vector;

public final class WorkQueue implements Runnable {
    private final Vector queue;

    public WorkQueue(final int nbThread) {
        queue = new Vector();
        for (int i = 0; i < nbThread; i++)
            new Thread(this, "WorkQueue-Thread-" + i).start();
    }

    public void execute(final Runnable runnable) {
        synchronized (queue) {
            queue.addElement(runnable);
            queue.notify();
        }
    }

    public void run() {
        while (true) {
            try {
                final Runnable runnable;
                synchronized (queue) {
                    while (queue.isEmpty()) queue.wait();
                    runnable = (Runnable) queue.firstElement();
                    queue.removeElementAt(0);
                }
                if (runnable != null) runnable.run();
            } catch (InterruptedException e) {
                // ignore
            } catch (RuntimeException e) {
                // ignore
            } catch (Throwable e) {
                e.printStackTrace();
            }
        }
    }
}
